Core B: SCIENTIFIC AND ADMINISTRATIVE COORDINATION CORE The objective of this Core Unit is to assure tight administrative coordination of the whole POI and to systematically organize continuing inter-component communication. The SAC Core will be overseen by the PI, and the lead Senior Administrator will be Jane Rigg. An Assistant Administrator is also on staff, and Caltech provides the necessary Grants Management and Accounting services. These same arrangements, in particular the administrative operations of Jane Rigg, have functioned successfully throughout the 9 years of the current POI. Eariier she administered many large and small projects, including Foundation and Program Projects, dating back to 1971.